Integral hinge and hinge bias structure



June 18, 1968 D. a. BALLANTYNE 3,338,420

INTEGRAL HINGE AND HINGE BIAS STRUCTURE Filed Sept. 15. 1966 INVENTOR.

h TTORNEY United States Patent F 3,388,420 INTEGRAL HINGE AND HINGE BIAS STRUCTURE David B. Bailantyne, Southfield, Mich, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Sept. 15, 1966, Ser. No. 579,651 4 Claims. (Cl. 16-150) This invention relates generally to hinge structures and more particularly to an improved integral hinge and hinge bias structure.

One feature of this invention is that it provides a new and improved plastic integral hinge structure having integral hinge biasing means. Another feature of this invention is that it provides a new and improved plastic hinge and hinge bias structure including a pair of hinge leaf portions swingably interconnected by a necked-down integral hinge, and an integral biasing portion connected between the hinge leaf portions in a manner to be resiliently deformable upon repeated relative movement between the hinge leaf portions for bias thereon without being subject to localized permanent deformation robbing it of its resiliency. Another feature of this invention is that the biasing portion is formed simply and economically of an elongated leg portion formed integrally at one end to one of the hinge leaf portions and connected at its other end to the other leaf portion in a manner to be twistable about its axis of elongation upon movement of the leaf portions relative to each other in one direction whereby to provide a bias in the other direction. Other features reside in provisions for prestress in the biasing portion, and the compactness of integral formation of the biasing portion with the two leaf portions.

These and other features and advantages of the invention will be readily apparent from the following specification and the drawings wherein:

FIGURE 1 is a fragmentary partially broken away perspective view of the hinge and binge bias structure of this invention as installed within a compartment and compartment closure structure;

FIGURE 2 is a perspective view of the hinge structure showing the biasing portion thereof in disconnected relation with the hinge leaf portions;

FIGURE 3 is a view similar to FIGURE 2 showing the hinge leaf portions in one relative position and the biasing portion in a prestressed operative relation connected therebetween; and

FIGURE 4 is a view similar to FIGURE 3 showing the hinge leaf portions in a second relative position.

Referring to FIGURE 1 of the drawings, the hinge and hinge biasing structure of this invention is shown installed Within a compartment box or structure provided with a cover or closure 12 adapted for movement between a closed position as shown and an open position, not shown. A hinge and hinge bias structure, designated generally as 20, has one hinge leaf portion thereof 22 suitably secured to a wall of box 10 and the other hinge leaf portion 24 thereof suitably secured to the closure 12 whereby to mount the closure 12 for movement between its positions relative to the box 10.

Referring to FIGURES 2 through 4, the hinge and hinge bias structure 20 is fabricated or molded of flexible plastic material into generally sheet like configuration. For the purpose of the integral hinging hereinafter discussed, the plastic material used should have the characteristics of high flex life and tensile strength, and the stock should 'be of sufficient thickness as to partake of the rigidity of the material to be self-sustaining as to form. At present, material such as polypropylene has been found to best provide these characteristics.

3,388,420 Patented June 18, 1968 As shown in the drawings, the two hinge leaf portions 22 and 24 are swingably interconnected by an integral hinge defined by a groove 26 formed in at least one side of the stock and providing a necked-down portion therein. Groove 26 may be formed either directly by molding or by cutting of the surface of the stock, or in the case of material such as polypropylene, by a repeated flexing of the initial flat stock along the line desired for the groove 26. By proper selection of material as aforenoted, the integral hinge is capable of long flex life under repeated swinging of the hinge leaf portions 22 and 24 from the generally unfolded, as fabricated position of FIGURES 2 and 3, to an abutting folded position as shown in FIG- URE 4.

The hinge and hinge bias structure 20 is fabricated to provide a central aperture or apertures and an elongated biasing leg 28 lying within the aperture and being generally of the same thickness as hinge leaf portions 22 and 24. One end of leg 28 is formed integral with hinge leaf 22 at one side of the integral hinge provided by groove 26. The other hinge leaf portion 24 is provided with an integral ear 30 at theopposite side of groove 26, and the free end of leg 28 has a generally cup-shaped formation 32 sized to be snugly nonrotatably received on the ear 30. Thus connected, leg 28 is resiliently twistable about its axis of elongation upon relative movement between the hinge leaf portions in one direction to provide bias in the other direction. The leg 28 may of course be formed integral at either end with the hinge leaf portions 20 and 22, but it is preferable that one end remain free so that it may be independently prestressed or twisted about its axis of elongation and subsequently interconnected between the two hinge leaf portions by placing the cup 32 over ear 30. This operation is shown in a comparison of FIGURES 2 and 3 wherein it is seen that with the direction of pretwist appearing in FIGURE 3, the leg 28 will seek to untwist in a direction biasing the hinge leaf portions to the abutting position of FIGURE 4. With a proper number of initial twists or turns to the leg 28, the leg remains stressed even when in full abutting position, thereby providing a predetermined degree of hold open or hold closed force on the two hinge leaf portions. In the installation shown in FIGURE 1, the hinge leaf portions move only to a half unfolded position allowing even less relaxation of the prestress on leg 28 and the closure 12 is accordingly held by significant bias in full closed position. The twist in leg 28 may of course be reversed to provide a hold open effect. I

It is seen from the proximity of the leg 28 at either end thereof to the groove 26 and the actuate angular relationship of the leg therewith, that it is insured that the leg will freely twist upon movement of the hinge leaf portions about the hinge line of the groove without undergoing any significant degree of bending at a point or points intermediate its ends which might cause localized permanent deformation within the leg sufiicient to rob it of its resilience. Further, it is seen that by the use of the configuration shown, the leg 28 remains generally within the surface confines or thickness of the two hinge leaf portions during hinging movement therebetween, and will not interfere with adjacent surfaces of box 10 or closure 12.

Having thus described the invention, what is claimed 1. In an integral hinge of the type constructed of flexible plastic material and including a pair of hinge leaf portions swingably interconnected by a necked-down integral hinge portion for substantially free swinging movement of one relative to the other between first and second positions, the improvement comprising an integrally formed elongated biasing portion connected between said leaf portions, said biasing portion having its axis of elon gation arranged relative to the hinge line of said integral hinge portion to be repeatedly resiliently deformable upon repeated relative movement of said one leaf portion from said first to said second position thereof, said biasing portion biasing said one leaf portion from said second to said first position thereof.

2. Integral hinge structure as recited in claim 1 wherein said biasing portion is arranged relative to the hinge line of said integral hinge portion to be resiliently twistable about its axis of elongation upon relative movement between said leaf port-ions.

3. Integral hinge structure as recited in claim 2 wherein said biasing portion is integrally formed at only one end thereof with a respective one leaf portion whereby such biasing portion may be independently twisted about said 4 one end for prestress in the first position of said leaf portions.

4. Integral hinge structure as recited in claim 3 including integrally formed means on the other end of said biasing port-ion and on the other of said leaf portions cooperable to connect said biasing portion and said other leaf portion.

References Cited UNITED STATES PATENTS 10/1966 Thomas 267l 4/1963 Foster 267-l 

1. IN AN INTEGRAL HINGE OF THE TYPE CONSTRUCTED OF FLEXIBLE PLASTIC MATERIAL AND INCLUDING A PAIR OF HINGE LEAF PORTIONS SWINGABLY INTERCONNECTED BY A NECKED-DOWN INTEGRAL HINGE PORTION FOR SUBSTANTIALLY FREE SWINGING MOVEMENT OF ONE RELATIVE TO THE OTHER BETWEEN FIRST AND SECOND POSITIONS, THE IMPROVEMENT COMPRISING AN INTEGRALLY FORMED ELONGATED BIASING PORTION CONNECTED BETWEEN SAID LEAF PORTIONS, SAID BIASING PORTION HAVING ITS AXIS OF ELONGATION ARRANGED RELATIVE TO THE HINGE LINE OF SAID INTEGRAL HINGE PORTION TO BE REPEATEDLY RESILIENTLY DEFORMABLE UPON REPEATED RELATIVE MOVEMENT OF SAID ONE LEAF PORTION FROM SAID FIRST TO SAID SECOND POSITION THEREOF, SAID BIASING PORTION BIASING SAID ONE LEAF PORTION FROM SAID SECOND TO SAID FIRST POSITION THEREOF. 